哪些因素(su)會影響植(zhi)物油脂的煙點

油(you)脂(zhi)(zhi)的(de)(de)煙點是油(you)脂(zhi)(zhi)質(zhi)量(liang)指標(biao)之一。煙點高(gao)的(de)(de)油(you)脂(zhi)(zhi)熱穩定(ding)性在(zai)一定(ding)時(shi)期內較好(hao),油(you)炸食(shi)品及(ji)(ji)烹飪操作環境衛生(sheng)條(tiao)件較好(hao),食(shi)品風味好(hao),但(dan)一味追(zhui)求(qiu)高(gao)煙點的(de)(de)油(you)脂(zhi)(zhi)產(chan)品,必將受加(jia)工(gong)過程高(gao)溫的(de)(de)影響,若工(gong)藝條(tiao)件控制(zhi)不當(dang),不但(dan)使油(you)脂(zhi)(zhi)發生(sheng)雙鍵的(de)(de)異構(gou)化及(ji)(ji)聚合(he),熔(rong)點升高(gao),降低(di)消化吸收率(lv)和營養價值,而且使油(you)中的(de)(de)天然抗氧化劑大大減少,儲存安定(ding)性降低(di),含油(you)食(shi)品貨架期縮短。因此(ci), 上海頎高(gao)儀器有限公司(si)生(sheng)產(chan)的(de)(de)HSY-20795D全自動油(you)脂(zhi)(zhi)煙點測定(ding)儀必須綜(zong)合(he)考(kao)慮油(you)脂(zhi)(zhi)產(chan)品的(de)(de)各項質(zhi)量(liang)指標(biao),選好(hao)工(gong)藝并(bing)把握(wo)好(hao)油(you)脂(zhi)(zhi)精煉各工(gong)序的(de)(de)工(gong)藝條(tiao)件,才能得到既品質(zhi)良好(hao),又(you)有較長(chang)儲存期的(de)(de)食(shi)用油(you)脂(zhi)(zhi)產(chan)品。

影響煙點的(de)因素(su)：

主(zhu)要(yao)內因。由(you)于游(you)離脂(zhi)(zhi)肪酸(suan)(suan)比(bi)甘油(you)(you)(you)酯容易揮(hui)發(fa)，精煉程度不(bu)同(tong)(tong)的(de)油(you)(you)(you)脂(zhi)(zhi)，游(you)離脂(zhi)(zhi)肪酸(suan)(suan)含量(liang)不(bu)同(tong)(tong)，其煙(yan)點(dian)測定值(zhi)不(bu)同(tong)(tong)。游(you)離脂(zhi)(zhi)肪酸(suan)(suan)含量(liang)相(xiang)同(tong)(tong)的(de)油(you)(you)(you)脂(zhi)(zhi)，以高碳酸(suan)(suan)為(wei)主(zhu)的(de)油(you)(you)(you)脂(zhi)(zhi)煙(yan)儀點(dian)高，以低(di)碳酸(suan)(suan)為(wei)主(zhu)的(de)油(you)(you)(you)脂(zhi)(zhi)煙(yan)點(dian)低(di)。如(ru)，椰(ye)子油(you)(you)(you)比(bi)菜籽(zi)油(you)(you)(you)的(de)煙(yan)點(dian)低(di)。皂化(hua)(hua)值(zhi)徊(huai)E甘三酯平均(jun)相(xiang)對分子質(zhi)量(liang)）相(xiang)近的(de)油(you)(you)(you)脂(zhi)(zhi)，在(zai)相(xiang)同(tong)(tong)酸(suan)(suan)值(zhi)條件下，碘值(zhi)高的(de)比(bi)碘值(zhi)低(di)的(de)油(you)(you)(you)脂(zhi)(zhi)煙(yan)點(dian)低(di)。如(ru)；棉籽(zi)油(you)(you)(you)（皂化(hua)(hua)值(zhi)9l一199，碘值(zhi)103—115）比(bi)花生(sheng)油(you)(you)(you)（皂化(hua)(hua)值(zhi)188：197，碘值(zhi)94一_9B1的(de)煙(yan)點(dian)低(di)，這(zhe)是由(you)于脂(zhi)(zhi)肪酸(suan)(suan)的(de)末飽和度越高，空(kong)氣中(zhong)加熱越易氧化(hua)(hua)分解出低(di)分子易揮(hui)發(fa)性組分。

目(mu)(mu)前國內各檢測(ce)(ce)機(ji)構(gou)和(he)企業均采用國家標(biao)準GB/T20795-2006《植物油脂(zhi)煙(yan)點(dian)測(ce)(ce)定(ding)(ding)(ding)(ding)》推薦的(de)(de)煙(yan)點(dian)測(ce)(ce)定(ding)(ding)(ding)(ding)方法(fa)。其(qi)中(zhong)，一法(fa)是采用自動(dong)測(ce)(ce)定(ding)(ding)(ding)(ding)儀方法(fa)（上海頎高儀器有限公司生產的(de)(de)HSY-20795D全自動(dong)油脂(zhi)煙(yan)點(dian)測(ce)(ce)定(ding)(ding)(ding)(ding)儀），第(di)二法(fa)是目(mu)(mu)測(ce)(ce)法(fa)。目(mu)(mu)測(ce)(ce)法(fa)通(tong)過肉(rou)跟觀察得到測(ce)(ce)定(ding)(ding)(ding)(ding)結果。測(ce)(ce)定(ding)(ding)(ding)(ding)人(ren)員眼睛觀察煙(yan)霧(wu)和(he)溫度(du)計(ji)讀數不，測(ce)(ce)定(ding)(ding)(ding)(ding)結果穩定(ding)(ding)(ding)(ding)性差。同時，樣品加熱速度(du)控制不準確(que)。因此，目(mu)(mu)測(ce)(ce)法(fa)受人(ren)為的(de)(de)因素(su)影響較(jiao)大，煙(yan)點(dian)測(ce)(ce)定(ding)(ding)(ding)(ding)誤差較(jiao)大。